package normalclass;

public class Demo {
    public static void main(String[] args) {
        Worker worker = new Worker();
        worker.name = "老王";
        method01(worker);    // 老王
        method02(new Worker());  // null
    }

    public static void method01(Worker w){
        System.out.println(w.name);
    }

    public static void method02(Person p){
        System.out.println(p.name);
    }
}
